Telephony.



PATENTJEID MAY 26, 1908. I. KITSEE.

TELEPHONY.

APPLICATION FILED APB..25,1904.

11VVENTOR.

. WITNESSES.-

J. LATTA, OF EHXLADELPHIA, PENNSYLVANIA.

returnees". L

no. esasov.

To all whom it may concern:

Be it known that I, lsinort KITSEE, of the city and county of Philadel his, State of Pennsylvania, have inventeu certain new and useful improvements in Telephony, of which the iollowin is s. specification.

My invention-re ates to an im roveinent in telephony and has more specie reference to telephonic transmission with one line not directly grounded.

In my experiments with telephonic transmission over comparative long distances and over lines in which artificially all conditions cl long lines were reproduced, l found that if a device consisting of two coils, such for instance as an inductoriuni, is connected with one coil to the line and with the second coil to the ground, either at one or both ends of the line, the sound could he distinctly heard. Having established such lines and having established communication through such lines, l lound that the interferences usually! accompsnying lines metcllically grounded. are also to a more or less degree present if the lines are grounded only inductively. In places, such as large cities, wherein through the running of electric cars'with rails as return, stray currents are encountered, and where other sources oi current greatly aiiect grounded Wires, it is necessary to counteract these earth currents and to do so, I have recourse to an arrangement whereby these ground influences are neutralized in a main, ner. so that they shall not encumber the line.

Referring to the drawing: Fi ures 1 and 2 are diagrammatic views einho .ying my invention; Fig. 1 illustrates diagrammatically two stations connected together with one lineand Fig. the windings inductorium consists.

in ZFig. l; A and A are two stations in ductively connected together through the line B; the'terrninals of said line are con nected through Wire C with one pole of the receiver l) and the other pole of said receiver is connected throu h Wir-e E with one terminal of the helix ll, the other terminal of said helix remaining free. In this helix is inserted the electro-msgnetic coil G grounded with one terminal at I through the Wire H; the second terminal of said coil remaining free.

in. Fig. 2, Fund G ere the helix and electromagnetic coil respectively. -'lhe elec- Specification of Letters Patent.

Application filed Ayril 2K5, 293%. Serial No. 92%,858;

2 represents diagrammatically of the two-coils of which the Patented May 28, 1908.".

tro niagnetic coil G consists of the two parts 3; and g, Wound in opposite direction to each other. A current, therefore, entering this coil will induce in the helix inipulses'in eccordance with the direction of the ccnvolotions of said coil, and as one half of said eonvolutions are Wound from right to left and the other half of the convolutions wound from left to I'l ht, it is obvious, that the ini pulses induce through said coil in '5 will. partially in one and partially in an opposite direction, thereby neutralizing each other. This function'oi a coil Wound as illustrated. in Fig. 2 is so well understood by persons versed in. the art that it IS unnecessary for me to go more into the detail of the principle whereon thisfunction is based; it sufilces to state, that in the windings of these coils care should be taken that the inductive influence of the same on the helix in which they are inserted should be erfectly neutralized, and it is best to make t hese coils in a. manner so that the same can eesilybe removed/or par tially withdrawn for l hove found that even if the coils consist of two halves, exactly alike and electrically c nnected together but Wound in opposition c\yto,each other, end the Whole arrangement inserted in a hne as illustrated, a source of interrupted current still causes slight disturbances in the receiver D and it is often necessary to With-' draw that end of thecoil which is connected to the line H partially out of the helix, so that the inductive influence oi the c oosing coil should be greater than the inductive influence of thct part which is connected to the ground.

I have illustrated the inductoriuin as consisting oftwo coils, the helix F and the electromagnetic coil G and l have illustrated the electro-inagnetic coil G as consisting of two Jarts wound in opposition to each other for t. e urpose of neutralizing the inductive effect or the impulses flowing therein, but it is obvious that instead of the electro-n1ag netic coil G, the coil of the helix F may con sist of two parts Wound in opposition to each other and in that case the coil of 5G maybe Wound in the usual manner without op osing parts. The eilect in hoth oases Woulc be the same.

Having now described my invention, What ll claim as new and desire to secure by Let ters Patent is:

l. in telephony, means to neutralize earth inf aieyi ces, the terminals of ssi line connects currents in a line of transmission, said means comprising an mductonum, one 0011 connected to the line of transmission, the second coil connected to the ground; one of said coils'oonstructed so that one part has-an inducin effect 0 posite to the inducing effect oft e secon partv 2. In telephony, a line of transmission, two-stations therefor, eaoh station equipped with necessary transmittin and receivin to one coil of a, converter, the second coil conees,5o7

nected to the ground, one of said coils constructed in a manner, so that one part is ISIDOR KITSEE.

Witnesses:

EDITH R. STILLEY. H. C Y'ETTER. 

